AVIM 103C Hydraulic Student PowerPoint 2

HOMEWORK ASSIGNMENT:

See 103C Syllabus

CLOSED-CENTER SYSTEM

CONSTANT DISPLACEMENT PUMPS Purpose: To create flow Constant displacement performance defined as being able to: Deliver a fixed volume of fluid per revolution (Cubic inches per revolution (e.g. .43 C.I. per Rev.)) Deliver a uniform rate of fluid flow (Gallons per minute (e.g. 3 GPM at 2800 RPM)) Pump rating defined as: Volumetric output at a given pressure (e.g. 3 GPM at 1500 PSI discharge pressure) Systems with Constant Displacement Pump Require: A device to unload the pump (an unloading valve for

discharge regulation) and a separate emergency relief valve.

PUMP TYPES AND APPLICATIONS

Vane 25 PSI and 10 in. Hg. Low pressure, high volume

External gear 1500 PSI Medium pressure, medium volume

Gerotor (internal gear) 1500 PSI Medium pressure, medium volume

Piston (bent axis or cam type) 3000 PSI and > High pressure, low volume

VANE PUMP

Vane Pumps

Dry Wet Pesco

Eclipse

Garwyn

Romec

Airborne (Edo)

Sigma-Tek

Tempest

Rapco

Wet Pneumatic Vane Pump Particulars

Eclipse Old and obsolete pump. Possible substitution with another pump.

Splined Coupling

All vacuum pumps, wet or dry on Continental and Lycoming horizontally opposed engines use the

same 12 tooth splined shaft.

Drive Speeds: Lycoming 4 cylinder: 1-1 Lycoming 6 cylinder 1.3-1 Continental 6 cylinder 1.5-1

Other Types of Drive Couplings

Eclipse

Romec

Dry Vane

Spline Coupling

Pump removed, coupling in engine accessory drive

Worn Spline Couplings

Looks like a different coupling, but it isnt.

Airborne (Pins sheared)

PESCO WET VANE PUMP

Wet Vane Pump

Drive Coupling

Torsional vibration minimized by circular springs

Installation Lubrication Test

Typical Wet Vane Pump Particulars Regulation required

Air/Oil separator required

Most pumps are bi-directional

Typical oil consumption 75 c.c. 213 c.c. per hour at 3750 RPM

Smaller volume pumps, for vacuum only; larger volume pumps, support vacuum and pressure

10 in. Hg. maximum suction; 16 in. Hg. pressure

Couplings: either tongue (old) or spline (newer) have shear sections and springs to minimize torsional vibration

Perform lubrication test before final installation

Average life ~ 1000 1200 hours

SUCTION REGULATOR

Inlet air regulation for: Gyro Instruments Pneumatic De-Icer Boots

Dry Vane Pumps

Exploded View

frangible drive coupling designed to fail at 250 in-lbs. torque

Examples of Dry Vane Pumps No Vise decal turns dark when

pump is overheated

Wear indicator window

Typical Dry Vane Pump Particulars Regulation required

Graphite vanes

Not all pumps are bi-directional

Some pumps have canted vanes

Standard AND200000 spline drive mounting

Garlock oil seal prevents engine oil entry

Improved designs have chamfered vanes and Teflon oil seals

Average life ~ 300 400 hours

Some pumps may be overhauled by CRS

Can be damaged during installation and when in service

Unexpected failure mode

Dry Pump Failure

AND20000 Drive Pad

Clockwise rotation facing engine pad

Internal Engine Splines - 26 teeth

TROUBLESHOOTING DRY VANE PUMP OVERHEATS

Dirty filter Kinked or blocked hoses Regulator mal-adjusted

BROKEN CARBON VANES OR ROTOR Pump has been dropped Teflon tape used on fittings Engine cleaning solvent entered pump housing Case was clamped in vise Poor pump overhaul worn case cavity

EXCESSIVE ENGINE OIL IN A WET PUMP Leaky pump mounting flange oil gasket

AIRBORNE VACUUM (DRY VANE) PUMP INSTALLATION TIPS

1. Never install a pump that has been dropped.

2. Clamp pump on mounting flange surface only. Clamping the housing will cause damage to the rotor or housing.

3. Change all filters in the system. Failing to do so could void the warranty on the pump.

4. Spray the fittings with silicone spray. Never use Teflon tape, pipe dope or thread lubricant.

5. Never tighten fittings on the housing more than one and one-half turns beyond hand tight.

6. Always replace all lock washers when installing a new pump.


7. Clean the pump inlet line thoroughly. 8. Blow out all hoses using high pressure

air before using. 9. Replace all old, hard, cracked or brittle

hoses. Sections of the hose liner may separate causing pump failure.


10. Use silicone spray on the hoses to slide them straight onto the fittings. Wiggling the hose from side to side can cause rubber particles of hose liner to be cut from the hose liner and damage the pump.


11. Double check the routing of the hoses. Improper routing could cause damage to the gyro system.

12. Cover the pump cooling ports before using Stoddard solvent to clean the engine.


SWEPT VANE PUMP FITTINGS

NOT SWEPT

NOT SWEPT

AWF 3P-194-AFC WET VANE PUMP

$1599 For aircraft without de-ice boots. New manufacture Airwolf wet vane air pump is based on the universally accepted and proven Garwin and Pesco oil-lubricated air pumps. Each new Airwolf 3P-194-AFC pump is test run for a full two hours and is covered by Airwolf's 2,000 hour/10 year warranty, a warranty that lasts the full life of your engine. Airwolf wet vacuum pumps are FAA PMA approved and are a direct replacement for all 200 series Airborne, Aero Accessories, Champion, Rapco, and Sigmatec Dry vacuum pumps and will also replace Pesco 3P-194 and Garwin wet pumps.Pump housing machined from billet aluminum with precision honed cast iron liner. Precision ball-bearing supported hardened steel rotor. Four oil impregnated soft graphite blades (4 times the thickness of standard dry pump vanes) No preference as to pump rotation, vanes will not shatter due to backfire or inadvertent reverse rotation. Internally engine oil lubricated 20-50 cc per hour.

$475 AWF AFC-W307 Walker Air/Oil Separator

EXTERNAL GEAR PUMPS

Electrically Driven Pumps

Controlled by a pressure

switch

Engine-Driven Pump

Figure 12-21 FAA-H-8083-31 Aviation Maintenance Technician Handbook Airframe, Volume 2

EXTERNAL GEAR PUMP FEATURES Medium pressure (up to 1500 PSI) systems Case and cover end or side ports Drive and driven gears Bushings Pressure loading port / check valve or internal

spring Case pressure port / check valve Shear shaft (pin); Tongue drive on older pumps (Seepage) drain ports

EXTERNAL GEAR PUMP COMPONENTS

EXTERNAL GEAR PUMP THEORY Fluid Power for Aircraft, Page 91

EXTERNAL GEAR PUMP ANIMATION

EXTERNAL GEAR-TYPE PUMP

Mechanical shear shaft will fail:

1. If the pump binds internally permits other accessories in gear train to function normally.

2. To protect the pump from overload system back pressure.


Case pressure (from internal seepage)

provides cooling, lubrication and internal sealing.

Pressure loading reduces internal leakage and prevents loss of pressure due

to case distortion.

PESCO EXTERNAL GEAR PUMP

GEROTOR PUMP

FIXED DISPLACEMENT PISTON

Stratopower Pump New York Air Brake Co. 1400 PSI AN# 4 Part# 67WF3002 SN - C2255 8 Contr. - NOA (s) 51-6 * 3 GPM@1500RPM -

3 WF-12-52 C2255 67B1109 Assy

AXIAL PISTON PUMP ANIMATION

Bent Axis Piston Pump

BENT AXIS (VICKERS) PISTON PUMP


High pressure, low volume (.35 c.i @ 3500 PSI) Pistons (usually an odd number) arranged in

cylinder block Odd piston number to reduce pulsation Universal link drives cylinder block Pistons reciprocate because of bent axis of

rotation Case pressure controlled by foot valve Caged ball bearing drive radial and thrust

bearings


High power to weight ratio: typically 2.5 hp/lb Volumetric efficiency 90% Typical displacement: .410 c.i./revolution Common rotational speed 3750 rpm or 1.5 x

crankshaft speed Designed for high RPM Low moment of inertia (fast start, fast stop) low

vibration Maximum stroke angle of 300 to minimize load


Changing direction of rotation: 1 foot valve rotate head 1800, reattach lines 2 foot valves Interchange pressure and

return lines Pump internal components (including bearings)

lubricated by hydraulic fluid Increasing Displacement:

Larger diameter pistons More pistons Longer stroke

Pump Vickers Inc. Detroit Model - PF92713 10ZE SN - X20475

HYDRAULIC PUMP TROUBLESHOOTING

TROUBLESHOOTING HYDRAULIC PRESSURE GAUGE FLUCTUATES

WHEN HYDRAULIC PUMP IS OPERATING Inadequate supply of hydraulic fluid

HIGHER THAN NORMAL HYDRAULIC PUMP TEMPERATURE Excessive internal pump leakage

HYDRAULIC PUMP CHATTERS DURING OPERATION Air leak at pump inlet line

HYDRAULIC FLUID FLOWING FROM PUMP DRAIN PORT (LINE) Worn hydraulic pump shaft seal

BROKEN SHEAR SHAFT Seized pump Unloading valve failure causing excessive pressure

PERISTALTIC PUMP: The fluid is contained within a flexible tube fitted inside a circular pump casing. A rotor with a number of rollers, shoes or wipers attached to the external circumference compresses the flexible tube. As the rotor turns, the part of tube under compression closes (occludes) thus forcing the fluid to be pumped to move through the tube. Additionally, as the tube opens to its natural state (restitution) after the passing of the cam, fluid flow is induced to the pump.

Typically used to pump clean or sterile fluids because the pump cannot contaminate the fluid, or to pump

aggressive fluids because the fluid cannot contaminate the pump. Some common

applications include pumping aggressive chemicals, high solid slurries and other materials where isolation of the product

from the environment, and the environment from the product, are critical.


See 103C Syllabus

VARIABLE DISPLACEMENT PUMPS

Variable Displacement

Fast response to system demand Pump unloading valve (pressure regulator) not

required System accumulator not required for control of

pressure surges, but may be installed for other functions

Principle of Operation Demand (effective stroke control) Stroke Reduction Intake Starvation

Variable Displacement Performance Ratings

The ability to withstand back pressure without internal leakage

Engine Driven Rated in gallons per minute at a specified

RPM (8 GPM at 3750 RPM) Electrically Driven

Rated in gallons per minute at a specified pressure (8 GPM at 3000 PSI)

STRATOPOWER DEMAND PUMP Fluid Power for Aircraft, Page 99

Four Sections

1. Mechanical Drive

2. Fluid Displacement

3. Pressure Control

4. Bypass

65WB06006 Pump

Rated @ 3000 PSI

13 GPM @ 3800 RPM

STRATOPOWER DEMAND PUMP

VICKERS STROKE REDUCTION PUMP Fluid Power for Aircraft,

Page 93

Stroke Reduction Principle

Stroke Reduction Pumps

KELLOGG STROKE REDUCTION PUMP Fluid Power for Aircraft,

Page 95

KELLOGG STROKE REDUCTION PUMP

STRATOPOWER INTAKE STARVATION PUMP

Fluid Power for Aircraft, Page 97

STRATOPOWER INTAKE STARVATION PUMP

Fluid Power

for Aircraft Page

98

Lockheed L-188 Electra and P-3

Orion

MOTOR-DRIVEN VARIABLE DISPLACEMENT

Advantages:

1. Ease of installation

2. Constant speed drive shaft

3. Not dependent on operating engine

4. Centrifugal-type boost pump to minimize cavitation

Disadvantages:

Size and weight

Opens at 3800 +/- 100 F.

MOTOR-DRIVEN VARIABLE DISPLACEMENT

15 20 PSI > existing reservoir pressure

Reduction gears - 3200 RPM

Performance rated in terms of GPM/Pressure

PUMP COMPENSATION

0 G.P.M. @ 2950 -3000 +150 / -0 PSI

8 G.P.M. @ < 2200 PSI

6 G.P.M. @ 2200 2950 +50 / -0 PSI

37.5 GPM @ 3750 RPM First stage centrifugal impeller

establishes 35 PSI to help prevent piston pump cavitation

Piston and Piston Shoe

HYDRAULIC POWER SYSTEM:

VARIABLE DISPLACEMENT PUMP Vickers PV3-160

Pressure Compensated Inline

Piston Pump

VARIABLE DISPLACEMENT PUMP

Variable Displacement Pumps Compensator responds to system pressure Engine or electrically driven Ports

Discharge Suction Case Drain

Possible integral bypass (relief) valve May have multiple stages to help prevent cavitation Depressurization valve (outlet) Fire valve (inlet) Parallel pump discharge check valves Quick disconnect fittings often provided

RAT

SAAB AJSF-37 Viggen

Republic F-105

Powers an electrical generator or hydraulic pump

POWER TRANSFER UNIT Fluid Power for Aircraft, Page 191

Airbus A320 APU "The Barking Dog"


See 103C Syllabus

DIRECT PRESSURE SYSTEM

DIRECT PRESSURE SYSTEM Adjust pressure relief valve with power control

valve held in the CLOSED position

Power Control Valves may be used in either open center or closed center

hydraulic systems.

POWER CONTROL VALVE

SURGE CYLINDER

A hand shutoff valve with an automatic turn-on feature. Pushing the plunger shuts off

pump flow to the reservoir. As an actuator reaches full travel,

pressure causes the valve to re-establish flow back to the

reservoir.

DIRECT PRESSURE SYSTEM

Typically 20% difference between kick in and kick out pressures

Typically opens (cracks) 20% higher than unloading valve kick out pressure

Typically cracks 40% higher than unloading valve kick out pressure

ELECTRICALLY CONTROLLED SYSTEM

MECHANICAL TYPE UNLOADING VALVE:

KICKED-IN POSITION

KICKED-OUT POSITION

Two springs work together to move to kicked out position

Springs oppose each other to move to kicked in position

Pressure Adjustment

Adjustment for Sluggishness

BALANCED PRESSURE-TYPE UNLOADING VALVE:

KICKED-IN POSITION KICKED-OUT POSITION

Reference Fluid Power for Aircraft, Page 56

BALANCED-PRESSURE TYPE Reference Fluid Power for Aircraft, Page 56

1. Bypass valve 2. From pump 3. Check valve

4. To accumulator 5. Piston 6. Spring

7. To reservoir

BALANCED-PRESSURE TYPE


VICKERS UNLOADING VALVE


FUNCTIONAL TEST 1. Test conducted as

close as possible to actual operating conditions.

2. Accumulator gas charge 1/3 of kick-out pressure.

3. Fluid input: 7.5 GPM (internally drained)

4. 10 GPM (externally drained)

BENDIX BALANCED PRESSURE REGULATOR:


1. Chattering Low reservoir level 2. Unloading valve cycles too frequently Low (or no) accumulator pre-charge 3. Accumulator does not charge with fluid (0 pressure) Broken (or missing) pilot valve spring Relief valve set too low 4. Early kick-in Leaky internal check valve 5. Late kick-out Leaky bypass spool 6. Will not bypass (unload) to reservoir Spools or plungers stuck in their bores

TROUBLESHOOTING

SYSTEM RELIEF VALVES Reference Fluid Power for Aircraft, Page 112

SYSTEM RELIEF VALVE 1. Adjusting Screw

2. Checknut

3. O-ring Packing

4. Main valve housing

5. Spring guide

6. Body

7. Ball holder assembly

8. Ball holder spring

9. Ball

10. Main valve

11. Main valve spring

SYSTEM RELIEF VALVE

1. Inlet body 6. Packing 11. Piston

2. Nut 7. Ring 12. Load spring

3. Gage 8. Sleeve 13. Spigot

4. Poppet spring 9. Packing 14. Outlet body

5. Poppet 10. Ring

SYSTEM RELIEF VALVE

Typical Cracking Pressure: 1650 PSI Free Flow Pressure: 1900 PSI Reseat Pressure: 1517 PSI

THERMAL RELIEF VALVE

Closed Open

Relief Valves Relief valves do not unload the pump Adjusted to open at cracking pressure Typical full flow and reseat pressures

approximately 10% higher and lower than cracking pressure

Cracking pressure can be affected by back pressure

Balanced relief valves and return manifold check valves are designed to minimize or reduce the effect of back pressure

Some relief valves are designed to reduce rapid opening and closing pressure

Unloading Valve Failed in Kicked-In Position

Higher than normal system pressure System relief valve will chatter or buzz Higher than normal fluid temperature

Adjustment Hierarchy

See aircraft maintenance manual for adjustment procedure (some relief valves are to be adjusted on a test stand, not while they are installed on the aircraft)

Highest to Lowest Thermal relief (valves) System relief valve Unloading valve

Adjustment may require jumpers to bypass valves in the circuit that open at lower pressure settings.

FLAP OVERLOAD VALVE

Installed in Flap Down Line

HYDRAULIC PRESSURE REDUCER

in2

in2

Downward Force

750 lbs.

100 lbs

Upward Force

750 lbs.

100 lbs

PRESSURE REDUCER Reference Fluid Power for Aircraft, Page 116

PRESSURE REDUCER:

PRESSURE REDUCER

PRESSURE REDUCER Reference Fluid Power for Aircraft

Page 116 and 117


See 103C Syllabus

THREE PORT SELECTOR VALVE

SELECTOR VALVE GLOBE TYPE

SELECTOR VALVE POPPET TYPE

Balanced and Unbalanced Types Stop pin limits travel

SELECTOR VALVE POPPET TYPE

1. O-ring gasket

2. O-ring packing

3. Sleeve

4. O-ring packing

5. Slide

6. Detent spring

7. Spring retaining bolt

8. Body

SLIDE TYPE SELECTOR VALVE

Most durable of selectors Lands and Grooves Detents

SLIDE TYPE SELECTOR VALVE

SOLENOID OPERATED SELECTOR 1. Override rod

2. Receptacle

3. Retainer

4. Lever assembly nut

5. O-ring

6. Plunger shaft

7. O-ring

8. Plunger

9. Stop

10. Selector sleeve

11. Selector slide

12. Valve body

13. O-ring backup ring

14. Pilot spring

15. Pilot slide

16. O-ring and backup ring

17. O-ring

18. Pilot spring

19. Solenoid coil

20. O-ring and backup ring

21. Detent stop

22. Plug

23. Position lock assembly (balls and spring)

24. Knob

25. Spring

SOLENOID OPERATED SELECTOR TYPES:

Full-Trail Power Off - both cylinder ports open to return

Half-Trail Power Off one or the other cylinder ports

open to return

Non-Trail Power Off both cylinder ports blocked to

return

Four-Way Servo Controlled Valve


CHECK VALVES

RESTRICTORS (ORIFICE) FIXED

ADJUSTABLE

INPORT OUTPORT

Adjustable needle valve

RESTRICTORS (ORIFICE)

SNUBBER AND PRESSURE GAUGE Snubber

dampens out system pressure

surges and prevents

oscillation of indicator pointer

Fitting assembly orifice restricts

flow. Pin is pushed and

pulled through orifice by

plunger, keeping it clear and at a

uniform size

ORIFICE CHECK VALVES

1. Outlet port 4. Inlet port

2. Cone 5. Orifices

3. Orifice 6. Orifice

CONE TYPE BALL TYPE

TYPICAL MARKING

METERING CHECK VALVE

METERING PIN

CHECK VALVE

PORT A TO ACTUATING CYLINDER

PORT B TO SELECTOR VALVE

E-1B 1500 PSI POWER SYSTEM

1. Main reservoir 2. Vent check valve 3. Vent filter 4. Ground test inlet 5. Left emergency hydraulic shutoff valve 6. Left emergency hydraulic shutoff valve switch 7. Right emergency hydraulic shutoff valve switch 8. Right emergency hydraulic shutoff valve 9. Emergency hydraulic shutoff valve circuit breaker 10. Ground test outlet 11. Engine driven hydraulic pump (2) 12. Quick disconnect (6) 13. Main relief valve 14. Autosyn transmitter (2) 15. Pressure snubber 16. A-C instrument bus 17. Hydraulic pressure indicator 18. Left hydraulic pump pressure gage circuit breaker 19. Right hydraulic pump pressure gage circuit breaker 20. Check valve (4) 21. Filter (2)

21

BYPASS CHECK VALVE M.O.C.V. (MANUALLY OPERATED CHECK VALVE)


Reference Fluid Power for Aircraft, Page 250 REGULATOR CONTROLLED SYSTEM

RATCHET VALVE

STATIC ON

Locks an actuator in a fixed position, preventing

movement in either direction. Especially

important if selector valve is left in the ON position

or selector valve has internal leakage.

RATCHET VALVE:

HYDRAULIC FIREWALL SHUT-OFF Electrically controlled valve shuts off hydraulic fluid flow to engine-driven pump in the event of an engine fire.

NAVY E-2

Visual position indicator (on the valve itself) is mechanically connected to the operating part of the valve and provides a positive indication of valve position.

Caution: Operating an engine with the firewall shut-off valve closed could cause severe damage to the engine-driven pump.

Shutoff Valves


HYDRAULIC FIREWALL SHUT-OFF S-2D Firewall Shut-Off

Valve Installation

QUICK DISCONNECT FITTING

AC65-15A Page 327: Valves are installed in the pressure and suction lines of the system just in

front of and immediately behind the power pump

QUICK-DISCONNECT FITTING Aeroquip 145 and 155 Series

provide a means of quickly connecting and disconnecting hydraulic lines without loss of fluid or entrance of air into the system, but do not eliminate the possibility of contaminants entering the system

QUICK-DISCONNECT FITTINGS

SCREW TYPE Proper tightening determined by visual inspection of lock spring or by feel.

QUICK-THREADING INDICATING TYPE Three equally spaced indicating pins on the socket half will

be extended when the halves are properly connected.

PUSH-PULL TYPE Connected by pushing mating halves together, disconnected by pulling back on the outer shell. STRAIGHT-FLOW BALL VALVE TYPE

In the connected condition, the lock ball on the socket half will protrude through the socket outer shell. When disconnected, the lock ball will be under the socket shell and will not be visible.

BALL-LOCK TYPE This type employs a cam ring and ball cage in the socket. When connecting, a distinct snap is heard and felt when the lock balls drop into the lock pocket indicating proper connection.

QUICK-DISCONNECT FITTING

Aeroquip 3200 Series

C-130 GROUND HYDRAULIC POWER

SHUTTLE VALVES

SHUTTLE VALVE

SEQUENCE VALVE

Mechanically Tripped

SIMPLIFIED LANDING GEAR SCHEMATIC

RETRACTION SCHEMATIC Reference AC65-15A, Page 350

PRIORITY (RELIEF) VALVE

No flow, Insufficient pressure to open the valve

Sufficient pressure to open the valve

Return flow in the opposite direction

HYDRAULIC FUSE

No flow condition

Normal flow condition piston is drifting to the right

Shut off condition piston moved fully to the right preventing flow

through the valve

Reverse flow condition piston is returned to the left

Reference Fluid Power for Aircraft Page 132 - 134

Hydraulic Fuse


HYDRAULIC FUSE

Boeing B737 Lear Model 60

HYDRAULIC FUSE TYPES

CROSSFLOW VALVE

FLOW CONTROL VALVE

FLOW REGULATOR:

Provides a constant outlet flow regardless of inlet pressure

PRESSURE SWITCH:

HYDRAULIC POWER SYSTEM:

T-2 HYDRAULIC POWER SYSTEM

Parker Aerospace Components


See 103C Syllabus

ACTUATORS PURPOSE:

Transforms fluid pressure into mechanical force (Transforms fluid flow into mechanical motion).

TYPES: Linear

Double Acting Balanced Unbalanced

Single Acting Rotary (hydraulic motor)

ACTUATORS BASIC TYPES: Fluid Power for Aircraft, Page 187

Brake Actuators Lock / Latch Actuators

Landing Gear Actuators (and other common

actuators)

Flight Control Actuators Servo Spool Actuators Nose Wheel Steering

Actuators Windshield Wiper Actuators

SINGLE ACTING ACTUATOR:

SINGLE ACTING ACTUATOR

UNBALANCED DOUBLE-ACTING ACTUATOR

RACK AND PINION ACTUATOR:

INTERNAL SNUBBER ACTUATORS: Fluid Power for Aircraft, Page 188

CUSHIONED ACTUATORS: Extend: Pressure is routed through the extend port into the feed tube. Fluid flow is restricted by metering rod. Piston head eventually contacts poppet, which slows movement by placing spring in compression. Unpressurized fluid is expelled from the retract port. Air is drawn into the outer chamber behind the piston.

Retract: Pressure is routed through the retract port to the outer chamber against the piston head. Piston retracts rapidly as unpressurized fluid in the inner chamber is forced through the feed tube and out through the extend port. Air is expelled from the outer chamber behind the piston.

CUSHIONED ACTUATORS:

Internal cylinders or piston sleeves permit equalizing of fluid displacement

Ball Lock Actuator Gear down and locked. Balls held in race detents by ball lock plunger; down lock switch actuated by piston shaft groove.

Ball lock plunger moves to the right causing balls to drop free from detents; plunger sleeve actuates down lock switch.

Down lock released. Piston shaft assembly retracts and unlocks gear.

Finger Lock Actuator

INTERNAL LOCK ACTUATORS Fluid Power for Aircraft, Page 189

LOCKING ACTUATORS:

Servo Actuator / Sloppy Link

Typical Hydraulic Servo. Figure 2-9 shows a typical hydraulic servo. In operation, when the pilot valve is displaced from center, pressure is directed to one chamber of the power piston. The other chamber is open to return flow. As the power piston travels the pilot valve housing travels because the two are attached. The pilot valve itself is being held stationary by the operator, and the ports again become blocked by the lands of the pilot valve stopping the piston when it has moved the required distance.

Figure 2-9. Hydraulic Servo Incorporating Sloppy Link and Bypass Valve. Servo Sloppy Link. Notice the servo sloppy link in Figure 2-9. It is the connection point between the control linkage, pilot

valve, and servo piston rod. Its purpose is to permit the servo piston to be moved either by fluid pressure or manually. The sloppy link provides a limited amount of slack between connecting linkage and pilot valve. Because of the slack between the piston rod and the connecting linkage, the pilot valve can be moved to an ON position by the connecting linkage without moving the piston rod.

Servo Actuator

Bypass valve permits manual servo movement when no operating pressure is available

Irreversible Valve

Used in helicopter servos in the flight control system to block the travel of feedback forces from their point of origin in the rotor head to the control stick

REDUNDANT ACTUATORS Fluid Power for Aircraft, Page 188

TANDEM ACTUATORS

HYDRAULIC MOTOR

HYDRAULIC MOTOR Fluid Power for Aircraft, Page 190

HYDRAULIC MOTOR Fluid Power for Aircraft, Page 100

POWER TRANSFER UNITS Fluid Power for Aircraft, Page 191

NOSEWHEEL STEERING

Rack and Pinion Actuator


NOSEWHEEL STEERING:

Differential Actuation


DIFFERENTIAL SYSTEM Fluid Power for Aircraft, Page 194

NOSEWHEEL STEERING Steering Damper Actuation


HYDRAULIC SERVO SYSTEMS

Aileron PCU

RUDDER POWER UNIT

SERVO-TYPE ACTUATORS

SERVO ACTUATOR

BELL 206 JET RANGER:

B-757 LEFT SYSTEM

B-757 CENTER

B-757 RIGHT

B-757 LEFT ENGINE INOPERATIVE PTU IN

USE

PTU IN

USE

B-757 BOTH ENGINES INOPERATIVE RAT IN

USE

LEAR 20

AILERON CONTROL: NAVY A-4

ELEVATOR CONTROL: NAVY A-4

RUDDER CONTROL NAVY A-5

Q ARTIFICIAL FEEL/FEEDBACK UNIT: Unit receives air data signal from the pitot-static system. The signal is used to modulate a control mechanism in the Q unit and operate a hydraulic load jack connected to the flight control system. The pilot is given feel that is directly related to aircraft speed and will greatly increase with aircraft speed. Q feel is popularly used in military / commercial aircraft that have a high speed and low control surface deflection. Spring feel is popularly used in aircraft that have a lower speed and higher control surface deflection.

B737 PCU


See 103C Syllabus

VENTURI TUBE

LOW PRESSURE PNEUMATIC SYSTEM:

LOW PRESSURE PNEUMATIC SYSTEM

HIGH PRESSURE PNEUMATIC SYSTEMS

ADVANTAGES OVER HIGH PRESSURE HYDRAULIC SYSTEMS:

Reduced fire hazard Limitless supply of fluid (with an on-board compressor) Less weight no system liquid weight and no return lines Small leakage may not cause rapid pressure drop Not sluggish in cold climates

DISADVANTAGES: Moisture accumulation may freeze and cause blockage System lubrication must be considered

PNEUMATIC COMPRESSOR:

Walter Kidde Compressor WK 890272 3000 PSI 2.4 SCFM

Hydraulic motor driven

HIGH PRESSURE COMPRESSOR

Built by Daveys Aerospace Division Keco Industries

HIGH PRESSURE PNEUMATIC SYSTEM:

MOISTURE SEPARATOR:

PNEUMATIC SOURCE:

PNEUMATIC DISTRIBUTION:

F-104 Utility Hydraulic System

F-104 Hydraulic System

YAK-52

B757-200 DOORS:

B757-200 EMERGENCY PNEUMATICS:

EMERGENCY PNEUMATIC SYSTEM:

B757-200 EMERGENCY PNEUMATICS:

EMERGENCY BRAKE SYSTEM:

PNEUMATIC SYSTEM SELECTOR:

PNEUMATIC SYSTEMS Fluid Power for Aircraft, Page 74

PNEUMATIC CYLINDER:

SPHERICAL PNEUMATIC FLASK


See 103C Syllabus

HYDRAULIC POWER SECTION Reference Fluid

Power for Aircraft, Page 216

LANDING GEAR SCHEMATIC Reference Fluid Power for Aircraft, Page 218

Dump Valve

BRAKE SYSTEM SCHEMATIC Reference Fluid Power for Aircraft, Page 220

NOSEWHEEL STEERING SCHEMATIC Reference Fluid Power for Aircraft, Page 221

CARGO-LOADING DOOR SCHEMATIC Reference Fluid Power for Aircraft, Page 222

MECHANICAL SEQUENCING SYSTEM: Reference Fluid Power for Aircraft, Page 223

WING FLAP HYDRAULIC SCHEMATIC: Reference Fluid Power for Aircraft, Page 224

AILERON BOOST SCHEMATIC: Reference Fluid Power for Aircraft, Page 225

In-Flight Refueling Systems

Self-locking, two position actuator Orifice check valves control rate of extension and retraction Check valve prevents return manifold surges from unlocking the extended actuator during flight Electrical and hydraulic power required for operational check Extension 5-7 seconds; Retraction 9-11 seconds

Reference NAVEDTRA 14315, Page 15-12

S-2D HYDRAULIC WINDSHIELD WIPER

P3-A HYDRAULIC WINDSHIELD WIPER

HOSE TESTING UNIT: Reference Fluid Power for Aircraft, Page 228

AIRCRAFT JACKS / JACK PADS: Reference Fluid Power for Aircraft, Pages 229 / 230

Aircraft Jacking

Ensure that all jacks are raised and lowered evenly to prevent the aircraft from tipping and falling off the jacks.

Use jack safety

collar to prevent

inadvertent jack

retraction.

MAINTENANCE STANDS Reference Fluid Power for Aircraft, Pages 232 / 233

Ground Support Equipment Know what required ground support equipment is

necessary for maintenance on your aircraft. Ensure ground support equipment is in proper

working order. Ensure people know how to use ground support

equipment. Observe the recommended scheduled maintenance

& calibration schedule on ground support equipment.

Never remove / tamper or modify built-in safety devices that are designed to work in ground support equipment.

GROUND SUPPORT EQUIPMENT

CESSNA HYDRAULIC TEST UNIT Reference Fluid Power for Aircraft, Page 234

Hose and Tube Proof Pressure Testing : Minimum of 30 s.

F-35 HYDRAULIC POWER SUPPLY Lockheed Martin has assigned the following internal identification numbers: Diesel PHPS LMIC# 2JSL00032-0001 (HII PN# 050170-100) Electric PHPS LMIC# 2JSL00021-0001 (HII PN# 050171-100) Capable of hydraulic fluid output operating pressures of between 4000 PSI and 6000 PSI and flow rates of between 24 GPM @ 4000 PSI and 10 GPM @ 6000 PSI, the dual system unit provides adequate hydraulic fluid pressure and flow for the JSF as well as a variety of other aircraft applications.

D-6 TEST STAND: Reference Fluid Power for Aircraft, Page 235

D-6 TEST STAND: Reference Fluid Power for Aircraft, Page 236

PORTABLE TEST STAND SPECIFICATIONS:

PNEUMATIC COMPRESSORS: Reference Fluid Power for Aircraft, Pages 240 / 241

MC-1 PNEUMATIC COMPRESSOR: Reference Fluid Power for Aircraft,

Page 242

Starting: 1. Always start with the clutch disengaged. 2. Always engage clutch at low, idle speed. 3. Put compressor in unload position

before the engaging the clutch. 4. Do not overt tighten moisture and relief

valve drains. Shutdown: 1. Unload the compressor before engine

shutdown. 2. Allow compressor to cool at fast idle

before disengaging the clutch (usually 2 minutes).

3. Allow engine to run with compressor disengaged for 5 minutes.

MC-1 PANEL: Reference Fluid Power for Aircraft, Page 243


See 103C Syllabus

TROUBLESHOOTING

SYSTEM DIVISION Most closed-center systems are divided into logical sub-sections: 1. Power Control (Normal / Emergency) Beginning at reservoir a. Power pump(s) Engine and/or electrically driven Constant displacement with regulator, variable displacement with

compensator, accumulator b. Auxiliary hand pump, secondary power pump, ram air turbine

(RAT) or power transfer unit (PTU) 2. Directional Control a. Hand operated selector valves b. Solenoid selector valves 3. Actuation a. Linear actuators double and single acting, balanced and

unbalanced full-travel and position selectable b. Hydraulic motors standard, reversible and speed/torque

governed

Correct fault isolation of a problem using a systematic approach.

1. Know and understand what normal operation is. How can you identify abnormal problems if you dont know what normal operation is?

TROUBLESHOOTING HIGHLIGHTS

2. Have available and study all schematics prior to troubleshooting. Schematics very frequently show direction of fluid flow. Its almost impossible to troubleshoot complex systems without one.


3. Isolate by sub-system first, then individual components one at a time assume only one failure at a time.

a. Logically reason that replacement of a component will solve the problem before component replacement.

b. Avoid shotgun troubleshooting unproductive, expensive and wastes time.


4. Consider the most likely component or item to fail first in the list of potential components and check the easiest items first.


5. Use and verify conditions using aircraft instrumentation where possible before using shop equipment.


TROUBLESHOOTING TIPS If no pressure is indicated on the system

pressure gauge, yet there is a return flow to into the reservoir, the trouble probably does not lie with the pump, but in the pressure control valves for the system. Pumps are fluid movers, not pressure generators. A pressure regulator or relief valve may be stuck open. Remember that pressure is created by confinement of fluid or resistance to flow.

With systems having a gauge mounted on the gas side of the accumulator, proper operation of the system pressure gauge may be verified by building pressure above the pre-charge level and observing that both gauges indicate the same pressure.

TROUBLESHOOTING TIPS

If there is a restriction in the pump outlet or between the pump outlet and the system pressure regulator, the system pressure will drop (gauge reading) when some unit is actuated. The pump is unable to provide the volume of fluid the system requires.


System pressure that is higher than normal could mean that the unloading valve (pressure regulator) is failing to unload the pump and a relief valve is maintaining the pressure.

Knowing the setting of each relief valve will help determine which valve is doing the work.

When a relief valve is controlling pressure, it frequently chatters, buzzes and becomes warm.

Also, an open system relief valve may cause a variable displacement pump to overheat as the pump is continuously delivering full flow in an attempt to build system pressure.


Lower than normal system pressure could be caused by faulty (open) regulating (relief) valve or a mis-adjusted pressure regulator.


A loud hammering noise is a system that has an accumulator may indicate an insufficient gas charge (preload) in the accumulator. As the pumps regulator kicks-in and kicks-out, the accumulator is not able to provide the cushioning effect of the gas charge. Verify gas charge by noting system pressure gauge reading on building pressure or releasing pressure. Some systems have a gauge mounted on the gas side of the accumulator.


TROUBLESHOOTING TIPS When normal system pressure

suddenly drops to zero as the pump stops, the accumulator may have lost the gas charge. Verify the proper pre-charge pressure and check for a leaking servicing valve.

Regulator chatter may be caused by low reservoir level. Insufficient accumulator gas charge may cause the regulator to cycle too frequently.


A broken or missing pilot valve spring or the system relief valve set too low will cause the regulator to bypass fluid to the reservoir. A leaky regulator check valve will cause early kick-in. A leaky regulator bypass spool will cause late kick-out.


TROUBLESHOOTING TIPS Failure of a variable displacement pump

compensator might be noted by loss of pressure or abnormally high pressure, depending upon mode of failure. Note: Normal pressure differential between full flow and zero flow is frequently only 50 PSI.

Pump chattering and subsequent overheating may indicate air at the inlet line of the pump. Causes might include a low reservoir level or a leak in the line between the reservoir and the pump.


TROUBLESHOOTING TIPS Slow actuation of a unit (slow moving

actuator) is often caused by internal leakage in a valve or an actuator. This leakage may also cause the regulator to cycle more frequently than usual. Electrically driven pump systems may show an excessive ammeter load when the actuator is moving. The motor is loaded for an abnormally long time. The leaking component may produce a hot-spot and become abnormally warm.

Spongy actuation is usually an indication of air in the system. Most double-acting systems are self-bleeding. If a component has been replaced, it should be cycled a number of times to purge air back to the reservoir. If the actuating time decreases each time the system is cycled, the air is being worked out of the fluid.


Note: Some systems do not purge air normally; special instructions are usually supplied by the airframe manufacturer to remove trapped air.



Regulating and relief valves are adjusted in a specific order. Highest opening pressure valves are set to relieve first, then valves with lower pressure settings. Jumpers and/or caps may be necessary to block some regulating and relief valves in order to reach the higher operating pressure of some valves.

Sometimes a hydraulic gauge fluctuates rapidly, with the pointer forming a blur. This may be an indication that there is air in the gauge line (inadequate supply of fluid from a low reservoir) or that the gauge is not adequately snubbed.


TROUBLESHOOTING TIPS Open-center hydraulic systems

only build pressure when selector valves are positioned to deliver hydraulic fluid to an actuator. When the selector valves are all in the neutral position, there should be no pressure indicated on the system pressure gauge.

Reference Fluid Power for Aircraft, Page 250 REGULATOR CONTROLLED SYSTEM:

2 3

1

Reference Fluid Power for Aircraft,

Page 255 Solenoid Selector Valve

De-Energized, fluid enters port 2 and

exhausts through port 3.

Solenoid Selector Valve Energized, fluid enters

port 2 and exhausts through port 1.

Figure 1.

HOMEWORK ASSIGNMENT:CLOSED-CENTER SYSTEMSlide Number 3CONSTANT DISPLACEMENT PUMPSPUMP TYPES AND APPLICATIONSVANE PUMPVane PumpsSlide Number 8Wet Pneumatic Vane Pump ParticularsSplined CouplingOther Types of Drive CouplingsSpline CouplingWorn Spline CouplingsPESCO WET VANE PUMPWet Vane PumpDrive CouplingInstallation Lubrication TestTypical Wet Vane Pump ParticularsSUCTION REGULATORDry Vane PumpsExploded ViewExamples of Dry Vane PumpsTypical Dry Vane Pump ParticularsDry Pump FailureAND20000 Drive PadTROUBLESHOOTINGAIRBORNE VACUUM (DRY VANE) PUMP INSTALLATION TIPSSlide Number 28Slide Number 29Slide Number 30Slide Number 31SWEPT VANE PUMP FITTINGSSlide Number 33EXTERNAL GEAR PUMPSElectrically Driven PumpsEngine-Driven PumpEXTERNAL GEAR PUMP FEATURESEXTERNAL GEAR PUMP COMPONENTSEXTERNAL GEAR PUMP THEORYEXTERNAL GEAR PUMP ANIMATIONEXTERNAL GEAR-TYPE PUMPSlide Number 42EXTERNAL GEAR-TYPE PUMPPESCO EXTERNAL GEAR PUMPEXTERNAL GEAR-TYPE PUMPGEROTOR PUMPSlide Number 47FIXED DISPLACEMENT PISTONSlide Number 49Slide Number 50AXIAL PISTON PUMP ANIMATIONSlide Number 52Bent Axis Piston PumpBent Axis Piston PumpBENT AXIS (VICKERS) PISTON PUMPBENT AXIS (VICKERS) PISTON PUMPBENT AXIS (VICKERS) PISTON PUMPBENT AXIS (VICKERS) PISTON PUMPBENT AXIS (VICKERS) PISTON PUMPSlide Number 60BENT AXIS (VICKERS) PISTON PUMPPump Vickers Inc. Detroit Model - PF92713 10ZE SN - X20475HYDRAULIC PUMP TROUBLESHOOTINGTROUBLESHOOTINGPERISTALTIC PUMP:HOMEWORK ASSIGNMENT:VARIABLE DISPLACEMENT PUMPSVariable DisplacementVariable Displacement Performance RatingsSTRATOPOWER DEMAND PUMPSlide Number 71STRATOPOWER DEMAND PUMPSlide Number 73Slide Number 74STRATOPOWER DEMAND PUMPVICKERS STROKE REDUCTION PUMPStroke Reduction PrincipleStroke Reduction PumpsSlide Number 79Slide Number 80Slide Number 81KELLOGG STROKE REDUCTION PUMPKELLOGG STROKE REDUCTION PUMPSTRATOPOWER INTAKE STARVATION PUMPSTRATOPOWER INTAKE STARVATION PUMPSlide Number 86Lockheed L-188 Electra and P-3 OrionMOTOR-DRIVEN VARIABLE DISPLACEMENTSlide Number 89PUMP COMPENSATIONSlide Number 91Slide Number 92Slide Number 93Slide Number 94Piston and Piston ShoeHYDRAULIC POWER SYSTEM:VARIABLE DISPLACEMENT PUMPVARIABLE DISPLACEMENT PUMPVariable Displacement PumpsRATSlide Number 101Slide Number 102POWER TRANSFER UNITSlide Number 104HOMEWORK ASSIGNMENT:DIRECT PRESSURE SYSTEMDIRECT PRESSURE SYSTEMPOWER CONTROL VALVEDIRECT PRESSURE SYSTEMSlide Number 110ELECTRICALLY CONTROLLED SYSTEMMECHANICAL TYPE UNLOADING VALVE:BALANCED PRESSURE-TYPE UNLOADING VALVE: BALANCED-PRESSURE TYPEBALANCED-PRESSURE TYPEVICKERS UNLOADING VALVEVICKERS UNLOADING VALVEFUNCTIONAL TESTBENDIX BALANCED PRESSURE REGULATOR:Slide Number 120SYSTEM RELIEF VALVESSlide Number 122SYSTEM RELIEF VALVESYSTEM RELIEF VALVESYSTEM RELIEF VALVETHERMAL RELIEF VALVERelief Valves Unloading Valve Failed in Kicked-In Position Adjustment HierarchyFLAP OVERLOAD VALVE HYDRAULIC PRESSURE REDUCERSlide Number 132PRESSURE REDUCERPRESSURE REDUCER:PRESSURE REDUCERPRESSURE REDUCERHOMEWORK ASSIGNMENT:THREE PORT SELECTOR VALVESlide Number 139Slide Number 140Slide Number 141Slide Number 142SELECTOR VALVESELECTOR VALVESELECTOR VALVE Slide Number 146SELECTOR VALVESELECTOR VALVESlide Number 149Slide Number 150Slide Number 151SOLENOID OPERATED SELECTORSOLENOID OPERATED SELECTORFour-Way Servo Controlled ValveCHECK VALVESSlide Number 156RESTRICTORS (ORIFICE)Slide Number 158RESTRICTORS (ORIFICE)SNUBBER AND PRESSURE GAUGEORIFICE CHECK VALVESSlide Number 162METERING CHECK VALVEE-1B 1500 PSI POWER SYSTEM BYPASS CHECK VALVESlide Number 166RATCHET VALVERATCHET VALVE:RATCHET VALVE:HYDRAULIC FIREWALL SHUT-OFFShutoff ValvesHYDRAULIC FIREWALL SHUT-OFF Slide Number 173Slide Number 174QUICK-DISCONNECT FITTINGSlide Number 176QUICK-DISCONNECT FITTINGSQUICK-DISCONNECT FITTING C-130 GROUND HYDRAULIC POWERSHUTTLE VALVESSHUTTLE VALVESlide Number 182SEQUENCE VALVESIMPLIFIED LANDING GEAR SCHEMATICSlide Number 185RETRACTION SCHEMATICPRIORITY (RELIEF) VALVESlide Number 188Slide Number 189HYDRAULIC FUSEHydraulic FuseHYDRAULIC FUSEHYDRAULIC FUSE TYPESSlide Number 194Slide Number 195CROSSFLOW VALVESlide Number 197Slide Number 198Slide Number 199FLOW REGULATOR:PRESSURE SWITCH:Slide Number 202HYDRAULIC POWER SYSTEM:T-2 HYDRAULIC POWER SYSTEMSlide Number 205HOMEWORK ASSIGNMENT:ACTUATORSACTUATORS BASIC TYPES:SINGLE ACTING ACTUATOR:SINGLE ACTING ACTUATORUNBALANCED DOUBLE-ACTING ACTUATORUNBALANCED DOUBLE-ACTING ACTUATORRACK AND PINION ACTUATOR:Slide Number 214INTERNAL SNUBBER ACTUATORS:CUSHIONED ACTUATORS:CUSHIONED ACTUATORS:Ball Lock ActuatorFinger Lock ActuatorINTERNAL LOCK ACTUATORSLOCKING ACTUATORS:Servo Actuator / Sloppy LinkSlide Number 223Irreversible ValveREDUNDANT ACTUATORSTANDEM ACTUATORSSlide Number 227HYDRAULIC MOTORHYDRAULIC MOTORPOWER TRANSFER UNITSNOSEWHEEL STEERINGNOSEWHEEL STEERING:DIFFERENTIAL SYSTEMNOSEWHEEL STEERINGHYDRAULIC SERVO SYSTEMSRUDDER POWER UNITSERVO-TYPE ACTUATORSSERVO ACTUATORBELL 206 JET RANGER:Slide Number 240B-757B-757 LEFT SYSTEMB-757 CENTERB-757 RIGHTB-757 LEFT ENGINE INOPERATIVEB-757 BOTH ENGINES INOPERATIVELEAR 20AILERON CONTROL:ELEVATOR CONTROL:RUDDER CONTROLQ ARTIFICIAL FEEL/FEEDBACK UNIT:B737 PCUB737 PCUB737 PCUHOMEWORK ASSIGNMENT:VENTURI TUBEVENTURI TUBELOW PRESSURE PNEUMATIC SYSTEM:LOW PRESSURE PNEUMATIC SYSTEMLOW PRESSURE PNEUMATIC SYSTEMHIGH PRESSURE PNEUMATIC SYSTEMSPNEUMATIC COMPRESSOR:Slide Number 263HIGH PRESSURE COMPRESSORHIGH PRESSURE PNEUMATIC SYSTEM: MOISTURE SEPARATOR:PNEUMATIC SOURCE:PNEUMATIC DISTRIBUTION:Slide Number 269F-104 Utility Hydraulic SystemF-104 Hydraulic SystemYAK-52Slide Number 273Slide Number 274Slide Number 275Slide Number 276Slide Number 277B757-200 DOORS:B757-200 EMERGENCY PNEUMATICS:B757-200 EMERGENCY PNEUMATICS:EMERGENCY PNEUMATIC SYSTEM:B757-200 EMERGENCY PNEUMATICS:B757-200 EMERGENCY PNEUMATICS:EMERGENCY BRAKE SYSTEM:PNEUMATIC SYSTEM SELECTOR:PNEUMATIC SYSTEMSPNEUMATIC CYLINDER:SPHERICAL PNEUMATIC FLASK HOMEWORK ASSIGNMENT:HYDRAULIC POWER SECTIONLANDING GEAR SCHEMATIC Dump ValveBRAKE SYSTEM SCHEMATICNOSEWHEEL STEERING SCHEMATICCARGO-LOADING DOOR SCHEMATICMECHANICAL SEQUENCING SYSTEM: WING FLAP HYDRAULIC SCHEMATIC:AILERON BOOST SCHEMATIC:In-Flight Refueling SystemsS-2D HYDRAULIC WINDSHIELD WIPERP3-A HYDRAULIC WINDSHIELD WIPERP3-A HYDRAULIC WINDSHIELD WIPERHOSE TESTING UNIT:AIRCRAFT JACKS / JACK PADS:Aircraft JackingSlide Number 306MAINTENANCE STANDSGround Support EquipmentGROUND SUPPORT EQUIPMENTGROUND SUPPORT EQUIPMENTCESSNA HYDRAULIC TEST UNIT F-35 HYDRAULIC POWER SUPPLYD-6 TEST STAND:D-6 TEST STAND:PORTABLE TEST STAND SPECIFICATIONS:PORTABLE TEST STAND SPECIFICATIONS:PNEUMATIC COMPRESSORS:MC-1 PNEUMATIC COMPRESSOR:MC-1 PANEL:HOMEWORK ASSIGNMENT:TROUBLESHOOTINGSYSTEM DIVISIONTROUBLESHOOTING HIGHLIGHTSTROUBLESHOOTING HIGHLIGHTSTROUBLESHOOTING HIGHLIGHTSTROUBLESHOOTING HIGHLIGHTSTROUBLESHOOTING HIGHLIGHTSTROUBLESHOOTING TIPSTROUBLESHOOTING TIPSTROUBLESHOOTING TIPSTROUBLESHOOTING TIPSTROUBLESHOOTING TIPSTROUBLESHOOTING TIPSTROUBLESHOOTING TIPSTROUBLESHOOTING TIPSTROUBLESHOOTING TIPSTROUBLESHOOTING TIPSTROUBLESHOOTING TIPSTROUBLESHOOTING TIPSTROUBLESHOOTING TIPSTROUBLESHOOTING TIPSTROUBLESHOOTING TIPSTROUBLESHOOTING TIPSTROUBLESHOOTING TIPSSlide Number 345Slide Number 346

AVIM 103C Hydraulic Student PowerPoint 2

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